Peel potatoes and cut into same sized chunks. Place into a pot, cover with cold water and add 2 tablespoons of kosher salt. Bring to a boil and continue to boil for 15 - 20 minutes until the potatoes are fork tender.
Reserve 1 cup of the potato water then drain potatoes.
Add the butter back into the pan over medium heat. Add the garlic and saute until fragrant. If you’re using granulated garlic, just stir it into the butter and let it cook for a few seconds until fragrant. Add the milk and ½ cup of the reserved water and bring just to a simmer. Remove from heat.
Pass the potatoes through a ricer into the pot. Mix until combined. Add more of the cooking water, if necessary, to give it a risotto-like texture. The potatoes should spread a little when served. Add salt to taste.